Tensioner - 90mm versus 76mm pulley?

[HerronScott]

Our 2002 has the 90mm tensioner pulley but it looks like Jeep used a 76mm pulley on later models (possibly after 2003?). Jeep shows the later part number with the smaller pulley as the replacement for the original part number so it looks like that's what I would get if I order the factory part or got the dealer to do this work (not planning on it).

For aftermarket, it looks like you can get both types so I'd like to know if there's any general wisdom here on which one I should get or if it even matters. I would love to know if Jeep moved to the smaller pulley later for technical reasons or if maybe it was just a cost reduction to save a few pennies.

Thanks!

Scott

 

[kejobe]

I'm not familiar with it, but I would assume that either would work. BUT, I would also assume that a shorter belt would be needed due to the pulley being smaller. I'm sure someone with more knowledge will chime in.

 

[JeepinJarhead03]

yea shorter belt is required for the smaller one

 

[GunnerSchenck]

Good a time as any to get a new belt!
Typically do if I replace a tensioner, but seems you won't have an option lol unless you decide to stay with the larger pulley

 

[HerronScott]

Yes looking at doing belt (and shorter belt is listed for the smaller pulley), water pump, thermostat, hoses and flush.

Scott

 

[GunnerSchenck]

Goin all in! I can dig it!

 

[HerronScott]

So no guidance or general wisdom from longtime owners as to which pulley is preferable (if either) or why Jeep might have made the change?

Scott

 

[tjkj2002]

yea shorter belt is required for the smaller one

Actually no it's not,only 1 belt listed for 3.7 KJ.

Funny thing is I change my tensioner and belt every 30k and never once ran into a pulley issue or being asked what pulley size.

 

[LibertyTC]

Here is a good read to add to this thread..
Link: http://www.jeepkj.com/forum/f196/jeep-kj-liberty-gates-tensioner-belt-56405/

 

[HerronScott]

Actually no it's not,only 1 belt listed for 3.7 KJ.

Funny thing is I change my tensioner and belt every 30k and never once ran into a pulley issue or being asked what pulley size.

RockAuto lists 2 Gates tensioners and belts at least for our 2002 with 1 inch length difference on the belts depending on the pulley size.

Gates tensioner with 90mm pulley 38167
Gates belt for 90mm pulley K060874 (87 7/8)

Gates tensioner with 76mm pulley 39120
Gates belt for 76mm pulley K060863 (86 7/8)

It looks like the 2002 and 2003 came with the 90mm pulley from the factory.

Scott

 

[HerronScott]

Here is a good read to add to this thread..
Link: http://www.jeepkj.com/forum/f196/jeep-kj-liberty-gates-tensioner-belt-56405/

I had found your thread when I searched for information on this. Great post with pictures!

Scott

 

[deboy922]

RockAuto lists 2 Gates tensioners and belts at least for our 2002 with 1 inch length difference on the belts depending on the pulley size.

Gates tensioner with 90mm pulley 38167
Gates belt for 90mm pulley K060874 (87 7/8)

Gates tensioner with 76mm pulley 39120
Gates belt for 76mm pulley K060863 (86 7/8)

It looks like the 2002 and 2003 came with the 90mm pulley from the factory.

Scott

Which one are you going to install? If I understand correctly, either one will work. You just want to use the correct belt/pulley combo. Your 2002 probably came with the 90mm pulley.

 

[HerronScott]

Which one are you going to install? If I understand correctly, either one will work. You just want to use the correct belt/pulley combo. Your 2002 probably came with the 90mm pulley.

I still haven't decided but I need to order the parts soon. I'm torn between installing what it came with versus not knowing if they went to the smaller one for some technical benefit. My fatal flaw is agonizing over small details like this even when it probably doesn't matter either way from what I'm hearing so far.

Scott

 

[tommudd]

I still haven't decided but I need to order the parts soon. I'm torn between installing what it came with versus not knowing if they went to the smaller one for some technical benefit. My fatal flaw is agonizing over small details like this even when it probably doesn't matter either way from what I'm hearing so far.

Scott

Way too much time spent on nothing really

 

[GunnerSchenck]

No benefit. Order the size it came with and replace it with the same length belt I'd say.

 

[tjkj2002]

No benefit. Order the size it came with and replace it with the same length belt I'd say.

There is only 1 belt for the 3.7(same belt as the 4.7).

 

[HerronScott]

There is only 1 belt for the 3.7(same belt as the 4.7).

Did you see that according to RockAuto's list, Gates lists different belts according to the pulley size?

Gates tensioner with 90mm pulley 38167
Gates belt for 90mm pulley K060874 (87 7/8)

Gates tensioner with 76mm pulley 39120
Gates belt for 76mm pulley K060863 (86 7/8)

Scott

 

[tjkj2002]

Did you see that according to RockAuto's list, Gates lists different belts according to the pulley size?

Gates tensioner with 90mm pulley 38167
Gates belt for 90mm pulley K060874 (87 7/8)

Gates tensioner with 76mm pulley 39120
Gates belt for 76mm pulley K060863 (86 7/8)

Scott

You can't believe 90% of what rockauto states.Like most parts places there books are way outdated and in most cases just plain wrong.They group together many models and years together and since the KJ is called the Cherokee in most of the world they lump XJ parts in with KJ parts.

Go to the dealer and your only got 1 choice for the 3.7/4.7.

 

[GunnerSchenck]

There's only one belt listed for my mustang too. But when I put underdrive pulleys on it I had to use a 2" shorter belt not listed for the car.. change the accessory run length, change the belt length. If I go to the dealership and say I need a belt for a 97 mustang, they'd only have one length listed. Just saying. Sure in your mind this is apples to oranges, but what's wrong with gates belts???

 

[tjkj2002]

There's only one belt listed for my mustang too. But when I put underdrive pulleys on it I had to use a 2" shorter belt not listed for the car.. change the accessory run length, change the belt length. If I go to the dealership and say I need a belt for a 97 mustang, they'd only have one length listed. Just saying. Sure in your mind this is apples to oranges, but what's wrong with gates belts???

Underdrive pulleys are a aftermarket mod.

So yes it's apples to oranges.........................

There is nothing wrong with Gates belts,one of the best out there.